화학공학소재연구정보센터
Indian Journal of Chemical Technology, Vol.15, No.2, 146-154, 2008
Adsorption of dyes on sawdust phosphate: Kinetics and equilibrium studies
The distribution coefficients, Kd, for navy brown 3REL, direct red, procion red H8B, methylene blue, metamega chronic yellow and lanasyn green 5 GL, solar violet and procion blue H5G from their aqueous solutions, at pH 3.2 and 7.5 on sawdust phosphate (SDP) have been reported. Effect of pH and added surfactant concentration on the percent removal of lanasyn green 5 GL has been studied. Percent dye removal increases with the decrease in pH. The applicability of the Freundlich and Langmuir equation has been tested for equilibrium data of which Langmuir isotherm model is found to be most appropriate. The values of Langmuir and Freundlich constants as well as the distribution constants show that SDP is a good adsorbent for all dyes, being better for basic dyes. The kinetics of adsorption of lanasyn green 5 GL on SDP was investigated at pH 3.2 and temperatures 25, 30, 35 and 40 degrees C. It is first order with respect to the dye and less than unity with respect to SDP. The values of k(ad), k(p) and k(f) at 30 degrees was found to be 2.18 x 10(-4) S-1, 15.33 x 10(-5) s(-1) and 20.72 x 10(-4) s(-1) respectively.